The excavation site can still be picked out today in the cadastral area called “Auf Burg”.

Nevertheless, the village's name did not appear among those listed in the 1387 “brotherly partition” between Counts Friedrich and Heinrich of Veldenz either.

In 1438, the fief passed to Hermann the Younger's son-in-law, Godelmann Blick von Lichtenberg.

In the Treaty of Meisenheim of 20 March 1595, Count Palatine Johannes I gave Merzweiler to the regents of Rhinegrave Christoph von Grumbach's sons, exchanging it for the villages of Bosenbach and Staufenbach.

At the same time, the Count Palatine was granted leave to develop the brine spring near Sankt Julian.

In the course of the treaty negotiations, Count Palatine Johannes had a report put together from which one can learn details from the late 16th century about Merzweiler.

It says that the Count Palatine was responsible for both high and low Oberkeit (something akin to “superiority”), could have incomes and levies at his disposal, and had hunting rights.

A serf here belonged, together with his family, to the Count of Palatinate-Veldenz, whose residence was at Lauterecken, but was nevertheless ready to show the Duke of Zweibrücken the customary subservience.

The Duke of Zweibrücken received from the Beth (tax) each year 1 Rhenish guilder, 4 Alben and 2 Pfennige.

Out of the wine tithes, one third each had to go to the Count Palatine, the Meisenheim parish priest and Antoni Bos's widow, meaning a rich landholder's family.

[9] During the time of the French Revolution and the Napoleonic era that followed, the German lands on the Rhine’s left bank were annexed by France.

As early as 1793, French Revolutionary troops advanced through the Glan valley and billeted themselves in the villages in the Grumbach area.

After the French were driven out in 1814, the Congress of Vienna established a new political order in post-Napoleonic Europe.

As part of this state, it passed by sale in 1834 to the Kingdom of Prussia, which made this area into the Sankt Wendel district within the Rhine Province.

Later, after the First World War, the Treaty of Versailles stipulated, among other things, that 26 of the Sankt Wendel district's 94 municipalities had to be ceded to the British- and French-occupied Saar.

After the Second World War, the village at first lay within the Regierungsbezirk of Koblenz in the then newly founded state of Rhineland-Palatinate.

In 1968, in the course of administrative restructuring, the Amt of Grumbach was dissolved, and Merzweiler was then transferred to the Kusel district, in which it remains today.

[10] Until a few decades ago, the greater part of Merzweiler's population earned its livelihood mainly at agriculture.

The earlier notion that the village already existed in Roman times with the name Martis Villa (Martis being the genitive of Mars, the war god, and thus this name would have meant “Mars’s Estate”) or Villa Mercis (“Warehouse Estate”) is not nowadays shared by regional historians.

That changed right away when Merzweiler was traded for Bosenbach and Staufenbach in 1595, and thereby ended up with the Rhinegraviate of Grumbach.

A 1584 ecclesiastical visitation protocol noted that the church had fallen into disrepair and needed to be renovated.

[1] The municipality's arms might be described thus: Per bend sinister Or a lion rampant sinister gules armed and langued azure and gules two roses, the smaller surmounting the larger, the larger reversed, both argent and barbed vert and the smaller seeded of the first.

The charge on the dexter (armsbearer's right, viewer's left) side is the lion once borne as an heraldic device by the Waldgraves and Rhinegraves, the area's last feudal rulers.

[15][16] The following are listed buildings or sites in Rhineland-Palatinate’s Directory of Cultural Monuments:[17] Merzweiler holds its kermis (church consecration festival) on the third weekend in August.

Primary income-earning operations mostly shifted to secondary income earners, but all together most of these businesses were reduced to a minimum.